Yes, we've been having problems with server overload stemming from a problem with a PHP extension we've added a few weeks ago for improving Audiofanzine (another site we run on the same server). Form time to time, this extension starts crashing without any reason. We're still investigating why this happens and if there is some workaround. On the meantime I've asked our admins to add sentinels to better detect those crashes and perform automatic restart of the server when this happens.